Image to Base64 Converter
Convert any image to a Base64 encoded string. Get the data URL, HTML img tag, and CSS background-image code ready to paste. All processing happens in your browser — your image is never uploaded.
About Image to Base64 Converter
Base64 encoding converts binary data — including image files — into a string of ASCII characters that can be safely transmitted and embedded in text-based formats like HTML, CSS, JSON, and XML. When an image is Base64 encoded, it no longer requires a separate HTTP request to load, which can improve performance for small images or in contexts where a file URL is not available.
A data URL (also called a data URI) combines the Base64 encoded image with a MIME type prefix so browsers can render it directly. A typical data URL looks like: data:image/png;base64,iVBORw0KGgo.... The data: scheme tells the browser this is inline data, image/png is the MIME type, and everything after the comma is the Base64 encoded image content.
Common use cases for Base64 images include embedding images directly in HTML email templates (which do not support relative URLs), embedding small icons in CSS files to eliminate HTTP requests, storing images in databases or JSON APIs, embedding images in SVG files, and using images in environments where file system access is restricted.
There is an important trade-off to consider: Base64 encoding increases the file size by approximately 33% compared to the original binary image. This means a 100 KB image becomes approximately 133 KB as a Base64 string. For large images, this overhead can negatively impact page load performance and is generally not recommended. Base64 is most beneficial for small images like icons, logos, and decorative elements under 10 KB.
This tool processes your image entirely in the browser using the FileReader API. Your image data is never sent to any server, ensuring complete privacy.
FAQ
Q: When should I use Base64 images instead of regular image URLs?
Use Base64 for small images (under ~10 KB) that are always needed on page load, in HTML emails where relative URLs don't work, when you need to embed an image in a JSON payload, or in offline/single-file HTML pages. Avoid Base64 for large images since the 33% size overhead and inability to cache the image separately outweigh the benefits.
Q: How do I use a Base64 image in HTML?
Use the data URL as the src attribute of an img tag: <img src="data:image/png;base64,iVBOR...">. The "Copy HTML img tag" button generates this code for you.
Q: How do I use a Base64 image in CSS?
Use the data URL as the value of the background-image property: background-image: url('data:image/png;base64,...');. The "Copy CSS background-image" button generates this code for you.
Q: Is my image data secure when using this tool?
Yes. This tool uses the browser's built-in FileReader API to convert your image to Base64 entirely on your device. The image data is never sent to any server, uploaded, or stored anywhere. You can use this tool with sensitive or confidential images safely.
Q: What is the difference between the Base64 string and the data URL?
The Base64 string is just the raw encoded image content (e.g., iVBORw0KGgo...). The data URL adds the scheme and MIME type prefix required for use in HTML and CSS (e.g., data:image/png;base64,iVBORw0KGgo...). For most web use cases, you need the full data URL.